Someone tried to make this coin look like an error by pressing another coin (or at least a section of another) into the obverse. The flattened reverse and fact that the coin is no longer round point to this. It could have been done with a vise or maybe a hit from a hammer. As noted above it was done outside of the mint and most likely long after the coin was struck.
The first US coin motto was found on a 1792 half disme and read: "LIB (erty) PAR (ent) OF SCIENCE & INDUSTRY"